Jan Rosenkranz

Stamped coal cakes in cokemaking technology: Part 1 – A parameter study on stampability

Abstract Coking of coal blends using high volatile coals with poor caking properties to produce a high quality coke for blast furnace application can be achieved by compacting the whole coal blend before pyrolysis in the so called stamp charge operation. Using stamp charging not only improves the flexibility of the coke making plant using cost efficient raw materials, but oven throughput is also increased. Therefore, in recent years, densification of coals has been introduced even to coals with good carbonisation properties when heat recovery ovens are used. At the Department for Mechanical Process Engineering and Solids Processing of the Technical University Berlin, the two subprocesses, densification and strengthening during stamping, were theoretically and experimentally investigated. The research work aims on the development of an integrated mathematical model, allowing the calculation of cake density and strength of the coal cake for a given coal blend depending on the stamping energy. The first part of this paper defines the overall process objectives and presents results from systematic investigations of the effects of several coal properties on the so called stampability as the integral model parameter for compacting. Surface moisture, coal granulometry and mechanical properties have significant influence on the densification. The incorporation of these parameters into the model allows the differentiated calculation of the cake density.

Stamped coal cakes in cokemaking technology: Part 2 – The investigation of cake strength

Abstract Coking of coal blends using high volatile coals with poor caking properties to produce a high quality coke for blast furnace application can be achieved by compacting the whole coal blend before the pyrolysis in the so called stamp charge operation. Using stamp charging not only improves the flexibility of the cokemaking plant using cost efficient raw materials, but also increases oven throughput. Therefore, in recent years, densification of coals has been introduced even to coals with good carbonisation properties when heat recovery ovens are used. At the Department for Mechanical Process Engineering and Solids Processing of the Technical University Berlin, the two subprocesses, densification and strengthening during stamping, were theoretically and experimentally investigated. The research work aims on the development of an integrated mathematical model, allowing the calculation of cake density and strength of the coal cake for a given coal blend and as a function of the stamping energy. In the first part of the paper, investigations on the stampability of coal blends were reported. In this paper, the development of a new strength test device for the systematic investigation of mechanical strength of coal compacts produced by stamping is described. Results from compressive strength tests indicate an elastic–plastic behaviour with failure by plastic fracture. Shear test results show similarity to the yield limit description in soil mechanics.

Process simulations in mineralogy-based geometallurgy of iron ores

Mineral processing simulation models can be classified based on the level that feed stream to the plant and unit models are described. The levels of modelling in this context are: bulk, mineral or ...